SkewCalculator.php
Calculates GC-skew, AT-skew, KETO-skew and GC content of a sequence window Freely inspired by BioPHP's project biophp.org Created 30 September 2026 Last modified 8 October 2026
Table of Contents
Classes
- SkewCalculator
- Migrated from biotools' Service/SkewsManager.php::computeImage() : the four per-window base- composition metrics it fed into its SVG plot, extracted as pure math with no rendering attached - that SVG plotting stays a biotools/UI concern. Unlike the legacy version, a window with an undefined denominator (e.g. no G or C at all, for GC-skew) returns 0.0 rather than dividing by zero - under PHP 8, int/int division by a zero denominator throws a DivisionByZeroError, which the legacy code would actually have hit for such a window ; this is a real, not hypothetical, edge case a sliding window can land on at a sequence's A/T-only stretch.